The popularity of on-line consumer markets is ever increasing. However, the nature of these on-line markets requires a certain amount of trust between the participating users, i.e., between the buyers and sellers. A participant's reputation has been widely accepted as one of the most common means of establishing trust among the users. Reputation in on-line consumer markets often takes the form of counters that specify positive and negative feedback from past transactions and/or some form of transaction analysis that aims to assess the likelihood that a specific user in the network will commit a fraudulent transaction.